In an IC chip packaging process, after certain steps, metal and/or metal ions may be deposited on the insulation layer between adjacent electrical connect structures, such as soldering balls (bumps), and soldering pads, etc. Such metal ions are generated by plasma etching processes, and/or wet etching processes, etc. For example, tin and/or tin ions may be deposited on the insulation layer between the adjacent tin soldering balls. Such metal and/or metal ions are able to cause a leakage current issue between the two adjacent electrical contact structures. Thus, the final test (FT) may fail.
In order to solve the FT failure caused by the deposition of the metal and/or metal ions, some technical approaches have been developed. For example, an argon plasma treatment process is performed on the insulation layer to remove the metal and/or the metal ions; and then the removed metal and/or metal ions are pumped away by the vacuum system of the plasma instrument.
However, in practical processes, using the argon plasma to remove the metal and/or metal ions has certain limitations because it is a physical process. The metal and/or metal ions may not be entirely removed. Further, the argon plasma may damage the surface of the dielectric layer. Thus, the leakage current may still be generated between adjacent electrical connect structures. The disclosed device structures and methods are directed to solve one or more problems set forth above and other problems.